1. Field of the Invention
The subject invention generally pertains to motors for vacuum equipment and more specifically to a gas/liquid separator for such a motor.
2. Description of Related Art
Motor-driven fans for creating a vacuum in equipment known as wet/dry shop vacs, wet carpet cleaners, water filtration units, water extractor units, etc., are exposed to a significant amount of moisture-laden air or foam. To reduce the amount of moisture drawn into the fan and/or motor, a rotating separator can be attached to the end of the motor shaft at the fan's inlet. A typical separator includes a series of peripheral fins that centrifugally sling water droplets outward away from the fan's inlet while allowing the air, which is lighter than the droplets, to enter the fan by passing between the fins.
Examples of such separators are disclosed in U.S. Pat. Nos. 6,391,101; 6,174,350; 6,162,287; 5,902,386; 5,096,475; 5,090,974; 5,030,257; 2,945,553; 2,221,572; and 2,102,353. Although these patented separators may be effective for their intended purpose, they all seem to have at least one of the following drawbacks.
One, in order to attach the separator to the end of the motor shaft, the shaft may need to be extra long to extend beyond its bearings so that one end of the shaft can extend through the separator and attach to the separator's end cap. Since many vacuum motors run at over 20,000 rpm, such an overextended shaft is more easily bent and may tend to vibrate, especially when the end of the shaft carries the weight of a separator.
Two, when the separator is fastened to the motor shaft by a nut screwed onto the end of the shaft, removing the separator for perioidic cleaning involves removing two parts, the nut and the separator. Although that may not seem like a significant problem, the nut is a relatively small part that may be accidentally dropped and lost in the dirt/water receptacle of the vacuum equipment.
Three, if the nut only fastens the separator to the motor shaft but also fastens other parts to the shaft, such as an impeller, sleeve, seal, spider bracket, etc., then the separator may be required in order to properly assembly and run the motor. Not being able to run the motor without the separator can be a disadvantage in dry vacuum applications where the separator is not needed. Thus, a company that manufactures motors for vacuum equipment manufacturers may need to produce one type of motor shaft for dry applications and another, longer motor shaft for wet applications.
Four, having a motor shaft with a fixed length extension for holding a separator of a particular size limits a motor manufacturer's freedom to vary the design of the separator to meet the particular needs of their customers (e.g., vacuum equipment manufacturers). Some customers may want a motor with a tall, narrow separator, and others may want one with a much shorter separator.
Consequently, a need exists for a separator design that allows motor manufacturers to vary the shape of the separator or even omit the separator altogether to meet the needs of their customers without having to also change the design of the motor shaft.